If we take producing plugins as a profession that we love, can we make a living here if we work full time?
Depends completely on what you create and where you are located but I doubt there are many achieving it with just plugins.
People like the guys behind the big sliders and page builders probably do but it takes a long time, require something special.
Thanks @charlie4282 for your feedback. May I know please what the location has to do with that?
cos it impacts the cost of living, what level of tax you pay etc.
Oh I see, thanks for clarifying @charlie4282 
I will work hard and try, hopefully it will work out with me,